\documentclass{article}
\usepackage[x11names, rgb]{xcolor}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{snakes,arrows,shapes}
\usepackage{amsmath}
%
%
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{0pt}%
\usetikzlibrary{automata}%

\begin{document}
\pagestyle{empty}
%
%
%

\enlargethispage{100cm}
% Start of code
% \begin{tikzpicture}[anchor=mid,>=latex',join=bevel,]
\begin{tikzpicture}[>=latex',join=bevel,]
  \pgfsetlinewidth{1bp}
\Huge%
\pgfsetcolor{black}
  % Edge: q1 -> q0
  \draw [->] (36bp,36bp) .. controls (36bp,48bp) and (36bp,64bp)  .. (36bp,88bp);
  \draw (45bp,62bp) node[auto] {$a$};
  % Edge: q0 -> q1
  \draw [->] (26bp,89bp) .. controls (21bp,79bp) and (16bp,66bp)  .. (19bp,54bp) .. controls (19bp,51bp) and (20bp,47bp)  .. (26bp,35bp);
  \draw (28bp,62bp) node[auto] {$a$};
  % Node: q0
\begin{scope}
  \draw [state] (36bp,106bp) ellipse (27bp and 18bp);
  \draw (36bp,106bp) node {$q'_{0}$};
\end{scope}
  % Node: q1
\begin{scope}
  \draw [state] (36bp,18bp) ellipse (27bp and 18bp);
  \draw (36bp,18bp) node {$q'_{1}$};
\end{scope}
%
\end{tikzpicture}
% End of code

%
\end{document}
%


